If I include "convo" in my list of activities, I mean that the provider is lots of fun to talk to and I elaborate in the ROS (while respecting her privacy, of course). My reviews so far have been of newbie friendly providers, so I think it is especially helpful for newbies. They're obviously going to be nervous and may have never hobbied before, so it helps a lot of them to know a bit about the provider's personality. Also, I think convo is especially important to bring up if the provider is a GFE-specialist.
The hobby for me is 50/50 enjoying the provider's skills and just spending time with a pretty woman I like in a no-strings-attached environment. I am very picky about which providers I see and greatly value a provider's personality. There are a lot of hot, skilled providers who I am not interested in seeing simply because I think there wouldn't be much chemistry. If I see a provider displaying a lot of wit, intelligence, or kindness in the forums or her reviews, she definitely moves up my list. In my line of work, I have to be hypercompetitive, manipulative, and mean to succeed. It's usually a lot of fun while I'm doing it, but it's not my personality at all and tbh it changes me for the worse. Spending an hour with a sweet, fun provider brings me right back to where I want to be. OTOH, I can 100% understand and respect how these things might be much less important to other hobbyists.
Chemistry is really important when it comes to having an amazing session, and for me, convo is huge. I find that the little things really make a big difference to me... TCB (huge!), convo/laughs, taking a few extra seconds on the good-bye hug, etc. Feeling appreciated and respected can be the difference between a fantasy that lasts an hour and a fantasy that stays with me for days/weeks/months.
And good convo can mean a lot of different things to me. I have been with a provider who was so intelligent that she actually tried to hide it because she was worried it would intimidate some clients. I was with another who was extremely shy and reserved, but she was a great listener and asked a lot of questions. Lots of styles can work!